Gas chromatography-mass spectrometry is an effective tool in organic chemistry and pharmaceutical studies for separating volatile chemicals by gas chromatography and identifying them by mass spectrometry fragmentation patterns. Among its many applications are API quantification, quality control, impurity identification, and screening for unknown compounds in complex biological samples and medication formulations. For thorough examination in the pharmaceutical sector, GC-MS is an essential instrument since it gives both quantitative (quantity) and qualitative (identification) data. The analytical technique known as gas chromatography-mass spectrometry (GC-MS) integrates the concepts of gas chromatography and mass spectrometry. The name gives it away: it's a hybrid approach to chemical mixture analysis that combines two separate methods. For testing samples taken from the environment, it is among the most reliable instruments. When working with complicated mixtures, GC-MS is useful for both qualitative and quantitative component identification and measurement. Metabolites that are volatile after derivatization, have a low boiling point, or have low polarity can be analyzed using GC/MS, the most advanced chromatography mass spectrometry coupling method. A few examples of where GC-MS has found use are in forensics (drug detection, explosives, fire, etc.), academia, astrochemistry, and the identification of previously unidentified samples. Materials that were believed to have decomposed irretrievably can now have their trace elements identified. When it comes to detecting and determining organic compounds, GC-MS is an essential and complementary tool in many field research, as seen in a few examples of its use. For the purpose of determining fuel composition, quality, and impurity identification, gas chromatography (GC) is widely utilized in the energy and fuel sectors for the analysis of volatile chemicals in petroleum products. Some of the many uses include keeping an eye on petrochemicals and natural gas, checking the purity of fuel, finding out how many octane numbers a given fuel has, assessing biogas, and helping with research and quality control for different hydrocarbon-based fuels. Modern gas chromatography (GC) methods, like high-temperature GC (HTGC) and multidimensional GC (GC×GC), enhance its applicability to molecules with higher boiling points and more intricate fuel matrices, and when coupled with mass spectrometry (GC-MS), it offers precise molecular identification.